Measurement And Research On Relative Contribution Of Frequency And Parameter Values To Selectivity For Interaural Correlation

With the advent of the digital age,consumers put forward higher requirements to the application of three dimensions(3D)technology,the emergence of 3D audio makes the traditional two-channel single-layer stereo sound field has been unable to meet the needs of the public.But with the number of channels increasing in the audio signal,a direct problem has been brought-the amount of data increases,which puts huge pressure on storage capacity and transmission bandwidth.So,how to compress the 3D audio signal effectively is the key problem that audio technology needs to solve.In order to compress the multi-channel signal efficiently,we can use a spatial parameter-based audio coding technique to quantify and encode audio signals.In this thesis,the multi-channel signal is transformed into a channel signal by downmixing based on spatial psychoacoustics,and the signal is encoded,the spatial positioning cues in each channel are extracted as edge information and coded independently.After receiving the transmitted data stream,the decoder reduces the mono signal and edge signal to the original multi-channel signal by the upmixing technique.Because the data of edge information is lower than mono audio signal,we can guarantee the audio quality under the premise of space parameters based on the audio signal for spatial audio coding,compress the audio signal effectively,reducing the storage space of the audio signal and the resources required for the transmission bandwidth.In order to quantify and encode the information efficiently,it is necessary to measure the perceived critical value of the human ear to the spatial parameters.In this thesis,we will test IC's JND with multi-parameter,then find its influence on the perceived size of the sound and its relationship with the frequency and IC parameter value,thus providing more comprehensive and more efficient compression for edge information.So,the main work of this thesis includes:1.Based on the theory of spatial psychoacoustics,optimizing and improving the previous listening system so that the audiometric software can be used to test IC's JND in full-band and multi-parameter values.2.Testing IC's JND in a variety of audio width and frequency,and record the results of each judgement.Then,the influence of interaural correlation on the perception of sound source localization was deduced from the experimental data.3.Interpolating and curve fitting the measured JND at more frequencies and IC reference values to obtain the more accurate JND-frequency-IC three-dimensional surface map,thus the relationship between JND value and the frequency and IC value(sound width)is obtained.